Photographic fluid container manufactured by freezing and sealing liquid

ABSTRACT

THE RUPTURABLE CONTAINER OF VISCOUS PROCESSING LIQUID OF A SELF-DEVELOPING PHOTOGRAPHIC FILM ASSEMBLAGE IS FORMED AND FILLED WITH AN ACCURATELY PREDETERMINED QUANTITY OF THE LIQUID BY FREEZING THE LIQUID TO FORM A SOLIDIFIED BODY, FORMING AND SEALING THE WALLS OF THE CONTAINER AROUND THE SOLIDIFIED BODY AND THEN THAWING THE SOLID BODY TO RETURN IT TO A VXCOUS, LIQUID STATE. A METHOD OF ASSEMBLING A FILM UNIT IS DESCRIBED IN WHICH A WALL OF THE CONTAINER COMPRISES A PORTION OF ANOTHER COMPONENT OF THE FILM UNIT.

E. LAND 3,695,884 PHOTOGRAPHIC FLUID CONTAINER MANUFACTURED BY Oct. 3,1972 FREEZING AND SEALING LIQUID 4 Sheets-Sheet 1 Filed June 18, 1970 Rm x 6 E/ww/n 6% M 290M 6. 0 15- ATTORNEYS Filed June 18, 1970 E. LANDPHOTOGRAPHIC FLUID CONTAINER MANUFACTURED BY 7 FREEZING AND SEALINGLIQUID 4 Sheets-Sheet 2 INVENTOR.

Emma/2104M a/naf ATTORNEYS Oct. 3, 1972 H E. LAND 3,695,884

PHOTOGRAPHIC FLUID CONTAINER MANUFACTURED BY FREEZING AND SEALING LIQUIDFiled June 18 1970 4 Sheets-Sheet 5 INVENTOR.

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@Jwum WM ATTORNEYS Y wmB kwwIm United States Patent 3,695,884PHOTOGRAPHIC FLUID CONTAINER MANUFAC- TURED BY FREEZING AND SEALINGLIQUID Edwin Land, Cambridge, Mass., assignor to Polaroid Corporation,Cambridge, Mass. Filed June 18, 1970, Ser. No. 47,452 Int. Cl. G03c 1/48U.S. Cl. 96-76 C 18 Claims ABSTRACT OF THE DISCLOSURE The rupturablecontainer of viscous processing liquid of a self-developing photographicfilm assemblage is formed and filled with an accurately predeterminedquantity of the liquid by freezing the liquid to form a solidified body,forming and sealing the walls of the container around the solidifiedbody and then thawing the solid body to return it to a viscous, liquidstate. A method of assembling a film unit is described in which a wallof the container comprises a portion of another component of the filmunit.

In the copending US. patent application of Edwin H. Land et al., Ser.No. 622,286, filed Mar. 10, 1967, abandoned and replaced by Ser. No.5,799, filed Jan. 26, 1970, and now Pat. No. 3,619,192, issued Nov. 9,1971, there is shown and described a photographic film unit comprisingall of the materials and components needed to produce a photographicprint including a rupturable container of a viscous, aqueous processingliquid adapted to be distributed within the film unit following exposurethereof to produce a transfer image. The basic components of the filmunit are a first or photosensitive sheet including a layer of alight-sensitive image-recording material such as silver halide, a secondsheet adapted to be superposed with the photosensitive sheet, at leastduring processing, to aid in the distribution of the processing liquidbetween the sheets in contact with the exposed photosensitive sheet anda rupturable container of the viscous liquid processing agent adapted tounidirectionally release the processing liquid in response to hydraulicpressure generated within the liquid by the application of compressivestress to the container.

In the particular form of the photographic film unit disclosed in theaforementioned application, the second sheet is initially secured insuperposition with the photosensitive sheet prior to exposure (madethrough the second sheet) and remains in superposition with thephotosensitive sheet following processing by viscous liquid distributedin a thin layer between the sheets. The processing liquid is provided ina container having walls formed of sheet material impermeable to theliquid and gas and sealed in face-to-face relationship around a cavityfilled with the processing liquid. The seal around one side of thecavity is weaker than the remainder of the seal and is adapted to becomeunsealed and form a passage for discharging the liquid contents of thecavity in response to hydraulic pressure generated within the liquid.The construction of this particular form of film unit is such that it isimportant to provide a very precise quantity of the processing liquid ina cavity having one dimension approximately equal to the width of thearea over which the liquid is to be distributed.

Accordingly, it is an object of the invention to provide a method offorming and filling a rupturable container of the type described with aprecise quantity of a viscous, aqueous processing liquid, the quantitybeing not less, and only very slight more, than that required to providea layer of uniform predetermined thickness over a predetermined areabetween the sheets.

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A number of advantages can be realized in the construction of a filmunit wherein the container is an integral portion of another componentof the film unit, for example, wherein a wall of the container is also asection of the second sheet. Heretofore container forming and fillingsystems have been designed to utilize, handle and perform a number ofoperations on the liquid and gas impervious sheet material of which thewalls of the container are formed, but have not been adapted to utilize,

handle and perform operations on other components of a completed orpartially completed film assemblage. On the other hand, film assemblymachines adapted to handle and assemble these other components are notreadily adapted to the handling of liquids and the filling ofcontainers.

Other objects of the invention are: to provide a novel and improvedmethod of forming and filling rupturable containers with a viscous,aqueous photographic processing liquid which may be performed byequipment that is not required to handle or contact the viscous liquid;and to provide a method as described in which the viscous liquid issolidified by freezing, thereby providing for more precise control overthe quantity of the container contents and the distribution of theliquid within the container as well as enabling film-manufacturingequipment to handle the liquid as if it were a solid.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the method involving the severalsteps and the relation and order of one or more of such steps withrespect to each of the otthers which are exemplified in the followingdetailed disclosure of a preferred embodiment taken in connection withthe accompanying drawings wherein:

FIG. 1 is a perspective view, partially in section, of a photographicfilm unit incorporating a rupturable container of processing liquidfabricated according to the method of the invention;

FIG. 2 is a somewhat schematic, elevational view illustrating the methodof the invention;

FIG. 3 is a perspective view of a solidified body of processing liquidillustrating a typical configuration of the solidified body;

FIG. 4 is a somewhat schematic, elevational view illustrating the methodof the invention;

FIG. 5 is a view similar to FIG. 1 illustrating a film unit manufacturedaccording to the method of the invention;

FIG. 6 is an exploded, perspective view of the film unit of FIG. 5; and

FIG. 7 is a somewhat schematic, perspective view showing the method ofassembling the film unit of FIGS. 5 and 6.

The rupturable container and/or fihn unit manufactured according to themethod of the invention comprises two opposed walls formed of amultilayer sheet material which is impermeable to the liquid and to gas.The walls are rectangular andare bonded to one another around theirmargins to define therebetween a shallow, elongated rectangular cavityfilled with the viscous processing liquid. The seal along one long sideof the cavity is weaker than the seal at the ends and at the oppositeside of the cavity and is adapted to become unsealed throughout itslength when compressive pressure is applied to the container. Thisweaker seal is approximately equal in length to the liquid-filled cavityso that the liquid is released and discharged from the container cavityin the form of an elongated mass approximately equal in length to thecavity. This basic type of container is well known in the art, beingdescribed in US. Pat. No. 2,543,181, issued Feb. 27, 1951 and embodiedin photographic film sold by Polaroid Corporation for use in itsself-developing cameras.

The container of processing liquid manufactured according to the methodof the invention is especially adapted for incorporation in a film unitof the type shown in FIG. 1 of the drawings in which the thickness ofthe materials comprising the film unit are shown as exaggerated forpurposes of clarity and illustration. This film unit, designated 10,comprises photosensitive or imagerecording sheet 12, a second orimage-receiving sheet 14 and a rupturable container 16 holding aquantity of processing liquid. Sheets 12 and 14 are preferablyrectangular and substantially coextensive with one another and arearranged in superposed face-to-face contact with at least one edge ofeach sheet aligned with one edge of the other. The two sheets areretained in superposed relation by mask sheet 20 in the form of arectangular sheet large enough to extend beyond the edges of both thephotosensitive and image-receiving sheets, secured in face-tofacerelation with the second sheet and having lateral edge portions at thesides and at one end folded around the sides and end of the superposedsheets and secured to the margins of the photosensitive sheet. Masksheet 20 is in the general form of a frame, having a large rectangularmedial opening defining the extent of the image produced in the filmunit, surrounded by lateral edge portions 24 and end portions 26 and 28.Image-recording sheet 12 includes lateral marginal portions 30 and endmarginal portion 34, and sheet 14 includes lateral marginal portions 32and an end marginal portion 36, the two sheets being located inface-to-face relation preferably with the edges thereof in alignment.The lateral edge portions 24 and end portion 26 of mask sheet 20 aresecured around and to, respectively, lateral marginal portions 30 and 32of sheets 12 and 14 and end marginal portions 34 and 36 of the sheets,elfectively binding the two sheets to one an other along three sidesthereof. In a preferred form of film units shown adapted to produce areflection print surrounded by a white border and viewed through thesecond sheet against a white background, at least mask sheet 20 isformed of an opaque white material and container 16 may also include awhite outer coating to provide a more aesthetically pleasing product.

Container 16 is of the type shown in US. Pat. No. 2,- 543,181 and isformed by :filling a rectangular blank of a fluid and gas impervioussheet material, medially and sealing the marginal sections of the blankto one another to form a cavity 18 for containing processing liquid. Theseal between longitudinal marginal sections 38 of the container isweaker than the end seals so that upon the application of a compressiveforce to the walls of the container in the region of the liquid-filledcavity and preferably, progressively from the opposite side of thecavity, there will be generated within the liquid hydraulic pressuresufficient to separate longitudinal marginal sections 38 throughout themajor portion of their length to form a discharge mouth at least equalin length to the length of the cavity. Container 16 is attached to thesheets of the film unit at the edges thereof opposite end portions 34and 36 preferably with a longitudinal edge of the container buttedagainst the edges of the sheets and with the discharge passage of thecontainer aligned with the facing surfaces of the sheets. Sheets 12 and14 include, respectively, end marginal portions 40 and 42 and the meansfor coupling the container to the sheets include end portion 28 of masksheet 20 secured to end marginal portion 42 of sheet 14 and longitudinalmarginal sections 38 of the container so as to bridge the gap betweenthe container and sheet 14; and a relatively narrow strip of tape 44secured to end marginal portion 40 of sheet 12 and the otherlongitudinal marginal section 38 of the container to bridge the gapbetween the container and sheet 12. The mask sheet 20 and strip 44cooperate to provide a liquidtight wall between the marginal sections ofthe container defining the discharge mouth thereof and sheets 12 and 14and form a conduit for conducting the liquid from the container betweenthe sheets at end marginal portions 40 and 42.

The film unit shown is characterized by an integral unitary structureconstructed so that its integrity may be maintained during and afterexposure and processing to produce an attractive photographic printprotected against injury or damage and having a uniform white bordersurrounding a well-defined rectangular image that extends to the border.This is accomplished by forming the second or image-receiving sheet of atransparent material and exposing the photosensitive sheet and viewingthe final image through the second sheet which functions to protect boththe image-recording medium and the final image. The transparentimage-receiving sheet and the image-record ing sheet may both be formedof conventional film base materials such as cellulose triacetate and arecoated on their inner surfaces with appropriate layers. The film unitmay be especially designed to produce a full color image and theimage-recording sheet will include at least a layer on its inner surfacea layer comprising a conventional image-recording medium such as silverhalide adapted to be exposed to produce an image.

Film unit 10 is of the type adapted to be processed, following exposure,by moving the film unit with container 16 foremost relative to andbetween a pair of juxtaposed pressure-applying members, first tocompress the container and eject the liquid contents of the containerbetween the photosensitive and second sheets 12 and 14 and then spreadthe processing liquid in a uniform thin layer between the sheets over anarea at least coextensive with opening 22 in mask sheet 20. Duringmovement of the film unit between a pair of pressure-applying memberssuch as rollers, compressive pressure is initially applied to container16 generating hydraulic pressure in the liquid within cavity 18effecting the rupture of the bond between longitudinal marginal portions38 of the container and the discharge of the liquid in the form of anelongated mass between sheets 12 and 14 and end marginal portions 40 and42. Continued movement of the film unit relative to and between thepressure-applying members causes advancement of the mass of liquidbetween the sheets toward the opposite end thereof as a thin layer ofpredetermined thickness between and in contact with the facing surfacesof the sheets. The film unit includes means for controlling thethickness of the layer of processing liquid distributed between thesheets specifically by appropriately spacing apart the pressure-applyingmembers. The spacing between the pressure-applying member and hence, thethickness of the layer of processing liquid is determined by thethickness of the film unit at the lateral margins thereof which in turnis a function of the thickness of photosensitive and second sheets 12and 14 and the thickness of lateral edge portions 24 of mask sheet 20.Since sheets 12 and 14 are of a substantially uniform thicknessthroughout, the thickness of the layer of processing liquid isdetermined by the thickness of mask sheet 20 and is approximately twicethe thickness of the mask sheet.

Spreading of the processing liquid to the edges of the area defined byopening 22 in the mask sheet and formation of a transfer image extendingto the edges of this area is insured by embossing sheet 14 at itsmargins to displace lateral marginal portions 32 and end marginalportions 36 and 42 out of the plane of the medial portion of the sheettowards sheet 12 by a distance or depth approximately the thickness ofmask sheet 20.

One means for insuring that there is sufiicient processing liquid toform a layer of predetermined thickness over the entire area encompassedby mask sheet 20 is to provide in the container a quantity of processingliquid in excess of the minimum quantity required to provide the desiredliquid layer. However, it will be apparent from the drawings that thefilm unit construction provides very little space for collecting andretaining excess processing liquid so that the quantity of excess liquidmust be minimized and the overall quantity of liquid very accuratelycontrolled. What space there is available for collecting and retainingexcess is located at the end of the film unit opposite container 16within end portion 26 of mask sheet 20 and is provided by making one ofthe sheets, for example, sheet 14, shorter than the other or forming theend sections of either or both sheets with notches (such as shown inFIG. 6).

The film unit illustrated and described herein may be adapted to beexposed and processed to produce a full color positive print and mayinclude all of the materials and reagents required to produce such aprint according to the process described in US. Pat. No. 2,983,606,issued May 9, 1961, in the name of Howard G. Rogers. A print of thistype may take the form of a multicolor dye-transfer image in a dyeablepolymeric layer supported on second sheet 14 between the latter and anopaque layer located behind the image between it and the photosensitivemedium. This opaque layer comprises the processing liquid, initiallyprovided in cavity 18 of container 16 in sufficient quantity to form anopaque layer of predetermined thickness, e.g., of the order of .004inch. The processing liquid preferably comprises an aqueous alkalinesolution having a high pH at which dye developers in the image-recordingmedium are soluble and diffusible, and contains an opacifying agent in aquantity sufficient to mask the dye developer retained in theimage-recording layer subsequent to processing and a film-formingviscosity increasing agent or agents to facilitate rupture of thecointainer and distribution of the liquid processng agent. Theopacifying agent normally will be present in a layer of liquid spreadbetween the transparent image-receiving sheet and the image-recordingsheet (which is preferably opaque) in a concentration sutficient tosubstantially limit, if not prevent, further exposure of theimage-recording medium by actinic light transmitted by the transparentimage-receiving sheet as well as to form a suitable background forviewing the dye-transfer image formed in the dyeable polymeric layer.Opacifying agents particularly desirable for incorporation in the liquidprocessing composition are those providing a white background forviewing the transfer image and particularly those compositionsconventionally employed to provide a background for photographicreflection prints and for having optical properties particularly suitedfor the reflection of incident radiation. As previously noted, theliquid should be quite viscous and contain a film-forming material insufiicient quantities to impart a viscosity, for example, in excess of100 centipoises at a temperature of 20 degrees centigrade and preferablyof the order of 100 to 200,000 centipoises at said temperature. Atypical liquid processing composition suitable for incorporation incontainer 16 for use in a film unit of the type described to produce adye transfer print is as follows:

A typical container structure for producing a dye transfer imageapproximately 3" square in a film unit of the type described may beformed by folding a rectangular blank of a suitable multilayer sheetmaterial having dimensions approximately 3.5 x 1.25", lengthwise andbonding or sealing the inner surfaces of the two walls to one anotheraround all four sides while forming a cavity adapted to containapproximately 0.9 gram of the processing liquid, the density of which isof the order of 1.6 grams per cc. The shape and size of the cavity andhence the shape and size of the mass of liquid contained therein aresubject to very accurate predetermination and in the typical containerdescribed by way of example, the cavity may take the form of arelatively thin, elongated parallelpipedon having tapered or bevelededges. In the particular example given, the dimensions may beapproximately 3 x 0.55 x .028". A typical water and gas impermeablesheet material for forming the Walls of the container and adapted to bebonded to itself by the application of heat and pressure is a multilayermaterial comprising a support sheet such as 1.25 mil. white opaqueglassine paper, an intermediate layer of lead foil approximately 1 mil.in thickness and an inner layer of a thermoplastic polymer such aspolyvinyl chloride approximately 1.5 mil. thick.

Reference is now made to FIGS. 2 through 4 of the drawings wherein thereis illustrated a method of forming and filling a rupturable container ofthe viscous processing liquid. The basic step in this method is coolingor freezing the aqueous processing liquid to form a solidified body ofthe liquid having the shape and dimensions of the intended liquid-filledcavity. This solidified body may then be handled as a solid rather thanas a viscous, adhesive and highly corrosive liquid, thereby greatlysimplifying the handling and packaging equipment required to fillcontainers. FIG. 3 illustrates a typical solidified body 50 ofprocessing liquid produced according to the method of the invention byapparatus such as illustrated in FIG. 2. Solidified body 50 aspreviously noted is generally rectangular, elongated, relatively thinand has beveled edges, the latter being provided to facilitate formingof the cavity and excluding air therefrom.

Body 50 may be produced in a number of different ways, for example asshown in FIG. 2, by depositing a layer or strip 52 of the processingliquid onto the surface of a drum 54 which is rotated continuously andis cooled as by circulating a refrigerant through the drum, to solidifyliquid layer 52 as it is deposited continuously on the drum.

Layer 52 is deposited on the drum. to substantially the desiredthickness by a doctoring nozzle 56 and additional control over thethickness of the layer may be had by providing a doctor blade 58 behindthe doctoring nozzle for reducing the thickness of the layer aftercooling thereof has commenced. The method of forming solidified bodies50 is continuous and the processing liquid is deposited or cast on andsolidified by drum 54 as a continuous strip 52 which is removed from thedrum and passes into a suitable cutting device for cutting thecontinuous strip into individual sections of the requisite dimensionshaving beveled or tapered edges. The strip or layer of processing liquidmay be deposited and solidified on drum 54 so as to have a width equalto the length of body 50 and the edges of the strip may be beveled asthe strip is formed by a variety of means including, for example,doctoring or planing the edges, or depositing the layer of liquid in achannel having inclined edges. The surface of drum 54 is provided with asuitable release coat and a scraper 59 may be provided for insuringremoval of any residue of the processing liquid from the drum ahead ofdoctoring nozzle 56. The physical properties, specifically, hardness andflexibility, of the hardened strip of processing liquid may beselectively controlled by varying the temperature to which theprocessing liquid is cooled. In the process illustrated, it is desiredto retain the strip of solidified liquid in a flexible condition topermit the strip which is cast on a cylindrical drum to be straightenedinto a planar configuration, the desired configuration of the podcavity. This is made possible as a result of the composition of theprocessing liquid, particularly the presence therein of the polymericfilm forming agent. It has been found that the liquid will besufiiciently solidified to permit handling as a flexible or plasticsolid at temperatures of the order of to F. and will retain someflexibility down to temperatures of the order of 25 F. In the solidifiedcondition the processing liquid is not only flexible but easily cut byconventional web severing and slitting equipment including shears,slitting knives and the like, and at such temperatures, may not bebrittle nor does it have a tendency to crack and shatter. This propertyof the strip or web of solidified processing liquid enables themanufacture of solidified bodies by casting strips having a width equalto either the length or width dimension of the solidified bodies andsevering the strip to the length of the other dimension; or casting astrip having a width which is a multiple of a dimension of thesolidified body and then slitting the strip to form a multiplicity ofstrips which are then cut into sections of appropriate length byconventional techniques.

In the method illustrated, solidified bodies 50 are formed by casting acontinuous strip having a width equal to the length of the bodies andthen passing the strip through a cutting device comprising, for example,a first roll 60 mounting a plurality of cutting blades 62 around itsperiphery and a backing roll 64 for supporting strip 52 against thecutting blades. Cutting blades 62 are shaped and mounted on roll 60 insuch a way as to cut the strip at an angle so as to bevel the edges. Inthis regard, it should be noted that opposite edges may be beveled inopposite directions as shown in FIGS. 1 and 3 or may be beveled in thesame direction as shown in FIG. 2. Following cutting solidified bodiesmay be loaded immediately into containers or they may be storedindefinitely in the frozen solidified condition. When the bodies areformed as a flexible curbed strip, they may be cooled still furtherafter having been straightened and cut, prior to loading.

Other systems may be employed for forming the solidified bodies ofprocessing liquid including, for example, extruding the liquid through adie having a cross section which is the same as the cross section of thesolidified bodies and cooling the die so that the liquid emerges fromthe die as a continuous strip which is thereafter cut into sections ofthe desired length. It should be apparent that the solidified bodiesadapted to be loaded into containers may be formed by any of a number ofconventional systems in which solids (such as metals) are formed bycooling and solidifying a liquid including, for example, casting andcooling the liquid in molds or the like. The solidified liquid hasanother property which enables the formation of bodies of preciselycontrolled dimension and this is the deformability ofthe solidifiedliquid which enables a strip or body to be further formed by manymethods similar to those employed in metal working such as by rolling orextrusion.

Containers may be formed and filled 'by advancing a strip or web 66 of amultilayer sheet material of the type described, through a folding dieor guide 68 which folds the strip longitudinally into a V-shapedconfiguration. The strip is then advanced through a heat-sealing stationin which the inner surfaces of the strip are heat sealed togetheradjacent the fold. The apparatus for performing these and the precedingoperations of the strip may be designed to operate on a continuouslymoving strip as shown or to operate on an intermittently moving stripdirecting periods when the strip is not in motion. Accordingly, theheat-sealing station is shown as a pair of heated rollers 70 forengaging and compressing the folded edge portion of the strip as it isadvanced continuously between the rollers. The strip passes from rollers70 to a filling station illustrated as a chute 72 for guiding asolidified body 50 into the V-shaped trough formed by folded strip 68.From the filling station the strip and body 50 are advanced to a formingstation in which strip 66 is pressed against the body to deform oremboss the strip so as to form a cavity containing the body and excludeair from the cavity. This is accomplished by applying compressivepressure to the two faces of the strip by suitable means such as a pairof rolls 74 formed of a pliable elastic material such as a foamelastomer. Alternatively or as an additional step in the process offorming the cavity which contains the liquid and excluding air from thecavity, the strip and body may be compressed between a pair of rigiddies having the desired configuration. The next step in the process issealing the two faces of the strip together around the remaining threesides of the cavity, that is, transversely at opposite ends of thecavity and along the longitudinal edges of the strip. This isaccomplished by compressing the strip between a pair of heated dies inthe form of a pair of heated rolls 76. The sealing of the container atthe ends and along one side of the cavity may be accomplished in asingle operation or in a sequence of operations in which the heat and/orpressure applied to the strips to form the end seals is greater than theheat and/or pressure applied to the longitudinal edge seal so as to forman edge seal adapted to become unsealed in response to hydraulicpressure generated within the liquid within the cavity. Thus the sealsmay be formed by employing a die having portions heated to differenttemperatures or by making the three seals in one step and applyingadditional heat and pressure to the end seals in one step and applyingadditional heat and pressure to the end seals in a succeeding step. Thecontainer thus formed may be subjected to an additional formingoperation, either before or after the liquid has been allowed to thaw,in which the container is compressed between a pair of forming dies,e.g., rollers. The last step in the process involves severing successivecontainers from the strip or containers. This is accomplished in theapparatus shown by a rotary knife 78 adapted to act against an anvil 80for severing the strip of containers as it is advanced between the knifeand anvil.

It should be noted that variations of this process and apparatus arepossible and these include, for example, fixed pairs of dies thatreciprocate toward and away from one another into and from engagementwith the strip which is advanced intermittently and is held stationaryduring engagement between the dies. It is also possible to vary theorder and sequence of some of the steps in the process; for example, thefolded edge seal may be made after introduction of the solid body; theend seals may be formed prior to introduction of the solid body; and/orthe container can be formed of two separate strips rather than a singlestrip; and/or the sides of the container may be oriented in horizontalplanes rather than generally vertically during filling and assembly. Byproviding the processing liquid as a solid body, the container formingand filling process assumes many attributes of a packaging processinvolving liquids, so that the apparatus may be substantially simplifiedinsofar as it is not required to handle and dispense a viscous andhighly corrosive liquid. This latter feature makes it possible to formall or a portion of the container from another component of the filmunit, such as for example, the second or image-receiving sheet.Ordinarily, film assembly operations and container forming and fillingoperations are carried out by different equipment because of the natureof the different problems involved, the latter type of equipment beingdesigned to handle the liquid involved whereas the film assemblyequipment is not designed to handle liquids, but is designed tomanipulate, form, and assemble solid materials usually in the form ofsheets or webs.

FIGS. 5 through 7 illustrate a film unit and a method of fabricating andassembling a film unit in which one wall of the rupturable container ofprocessing liquid is a section of the second or image-receiving sheet.This film unit designated 82 is basically similar in both constructionand function to film unit 10 and comprises a rectangular photosensitivesheet 84, a second or image-receiving sheet 86, and a mask sheet 88.Second sheet 86 includes a first section which is generally rectangularand includes a rectangular medial embossed region in which the image isformed and a smaller end section contiguous to the first section andadapted to form one wall of a rupturable container. This end section,designated 90, is coated on one surface with at least a layer ofthermoplastic material and preferably with a plurality of layers adaptedto render the end section impermeable to the processing liquid and togas. These materials are essentially the same materials which comprisethe container previously described. S'econd sheet 86 may be formed, forexample, of mil. cellulose triacetate rendered liquid and gasimpermeable by laminating a 1.0 mil. film of lead to the end section,employing a suitable adhesive and coating the lead film with a 1.5 mil.layer of polyvinyl chloride.

The photosensitive sheet 84 is secured to second sheet 86 by mask sheet88, the edge portions of which are adhered to the outer face of thefirst section of second sheet 86 around the margins of the embossed areaand are folded around the end and lateral edges of the sheets and areadhered to the margins of the photosensitive sheet. The material of themask sheet may comprise white paper coated on the surface adapted to beheat sealed with a conventional heat sealing material such asplasticized nitrocellulose. Mask sheet 88 may extend the full length ofthe film unit as shown in FIGS. 5 and 6, or it may be slightly shorteras shown in the first embodiment of the film unit.

The continer of film unit 82 comprises a pair of walls sealed togetherin face-to-face relation around a liquid filled cavity and, in the formshown, one wall is defined by end section 90 of second sheet 86 and theother wall is defined by a rectangular cover sheet 92 formed of a liquidand gas impermeable laminate, such as previously described, sealed toend section 90 with an edge of the cover sheet butted against the edgeof photosensitive sheet 84. A narrow strip or tape 94 is secured inoverlapping relation to the longitudinal edge portion of cover sheet 92defining one side of the discharge passage of the container and theadjacent edge portion of photosensitive sheet 84 for conducting theliquid from the container between the photosensitive and seconds sheets.The cavity of the container is formed by conforming or embossing coversheet 92, while end section 90' remains in a substantially planarcondition, to the shape of the liquid content of the cavity illustratedin FIG. 6 wherein the liquid is shown as a solid body 96 all four sidesof which are beveled in the same direction so that the cross sectionalconfiguration of the liquid body is a bilaterally symmetric trapezoid.

The operations involved in the fabrication and assembly of film units 10including the forming and filling of the containers, are illustrated inFIG. 7. This process is an essentially continuous assembly line processin which the materials are advanced either continuously orintermittently through various stations of apparatus which form and/orassemble the various components of the film units. The continuousassembly operation in which mask sheet 88 functions as a carrier for theother components of a sequence of film units is the subject matter ofapplication Ser. No. 135,539, filed Apr. 20, 1971, and commonly assignedherewith. Second sheet 86 is provided in elongated form as a strip orweb having a width equal to the length of the film unit and coated alongone edge portion 90* with the laminae which form one liquid and gasimpervious wall of the container. Second sheet 86 is embossed and thenadvanced to a cutting and laminating station in which sheet 86 islaminated to an elongated mask sheet 88 which has been preformed withrectangular apertures and notches in the margins where the elongatedsheet is eventually cut into individual sheets. Mask sheet 88 islaminated by heat sealing to the leading portion of each successivesecond sheet 86 ahead of the position at which the second sheet issevered, and following severance of the second sheet, the remainingportion of the second sheet is laminated to the mask sheet which thenfunctions as a carrier to support and advance the succession of secondsheets through the remaining operations in the assembly process. Theindividual second sheets 86 are mounted on the mask sheet is spacedrelation so that the portions of the mask sheet intermediate adjacentsecond sheets constitute the lateral marginal portions of the mask sheetwhich are subsequently folded around the sides of the film unit andadhered to the lateral margins of the photosensitive sheets.

During the next steps in the process, a solidified body 96 is depositedon the coated edge section of sheet 86, andv a cover sheet 92 isimmediately applied in covering relation to body 96 and the edge sectionof sheet 86 and compressed against the solidified body to form a cavitycontaining the body While excluding air from the cavity The next twosteps in the process may be performed simultaneously at the same stationof the apparatus or in succession, with the first of these beingapplying heat and pressure to the cover sheet and section of sheet 86around the margins of the cavity to form the sealed container andlocating photosensitive sheet 84 in proper position on the embossed areaof second sheet 86 with the lateral and one end edge of thephotosensitive sheet aligned with the corresponding edges of the secondsheet. The operations in which the solidified body is deposited on thesecond sheet, the cover sheet is applied and compressed, and heat sealedto the second sheet should be performed in relatively rapid successionso that heat sealing of the container is completed before the frozenliquid returns to a liquid state. This melting time is a function of thetemperatures of the solidified body, the coated section 90 of the secondsheet and the cover sheet, and may be extended by lowering thetemperature of any one of the three components that are assembled toform the liquid filled container.

The succeeding operations in the assembly process include applying andheat sealing a tape to the adjacent edges of the container and theimage-recording sheet and severing the container cover sheet and thetape overlapping the container and photosensitive sheet; folding the endmarginal section of the mask sheet around the edges of thephotosensitive and second sheets; and heat sealing the marginal endsection of the mask to the photosensitive sheet. Thereafter the masksheet is cut midway between successive photosensitive sheets so that theremaining operations in the assembly process are carried out onindividual, unconnected film units. These latter operations involvefolding the lateral marginal portions of the mask around the edges ofthe photosensitive and second sheets and heat sealing the lateralmarginal portions of each mask sheet to the margins of thephotosensitive sheet to complete assembly of each film unit.

It will be noted that during the assembly process, the processing liquidis in the form of a solid body rather than a viscous, highly corrosiveliquid and is handled in the same manner as the other components of thefilm units. The assembly process may be carried out continuously orintermittently, the former, in which the sheet materials are incontinuous motion throughout the various stations and assemblyoperations and the latter in which operations are performed while thematerials are stationary at least with respect to the apparatus. It willbe seen that solidifying the viscous, aqueous processing liquidfacilitates the assembly line production of complete selfdeveloping filmunits, each containing a precisely predetermined quantity of theprocessing liquid in a rupturable container without the necessity in theassembly apparatus for special liquid handling equipment.

Since certain changes may be made in the above method without departingfrom the scope of the invention herein involved, it is intended that allmatter contained in the above description shall be interpreted asillustrative and not in a limiting sense.

What is claimed is:

1. In a process of manufacturing a photographic product comprising acontainer including a pair of walls substantially impermeable to fluidsand at least one of which is formed of a flexible sheet material, joinedto one another to form a cavity filled with a viscous liquid compositionand having a sealed passage adapted to become unsealed to effect theunidirectional release of said viscous liquid in response to theapplication of compressive pressure to said container, the improvementcomprising:

cooling a viscous, aqueous liquid photographic processing compositionadapted to at least activate a photographic developing agent, to form asolidified body having the configuration of the container cavity to beformed and filled with said liquid;

compressing said walls against each other and said solidified body toform a cavity by causing at least said one wall to conform to said bodyand exclude gas from said cavity between said walls;

sealing said walls to one another in face-to-face relation along atleast three sides of said cavity, the seal between said walls on oneside of said cavity being approximately equal in length thereto andbeing weaker than the other seals to constitute said sealed passage; and

thawing said solidified body to return said body substantially to itsoriginal liquid state while retaining the configuration of said cavitysubstantially unchanged.

2. In the process defined in claim 1, beveling the edges of said bodyaway from one side and introducing said body between said walls withsaid one side located adjacent said one wall.

3. In the process defined in claim 1, depositing said liquid on thesurface of a supporting member as a layer of substantially the samethickness as said body, cooling said supporting member to solidify saidliquid, removing the solidified liquid from said surface and cutting thesolidified liquid to said size and shape.

4. In the process defined in claim 1, extruding said liquid continuouslythrough a die while cooling said liquid to form an elongated striphaving a cross-sectional configuration conforming to said cavity anddividing said elongated strip into sections, each constituting one ofsaid bodies.

5. In the process defined in claim 1, embossing said walls substantiallyto the shape of said cavity prior to the introduction of said solidifiedliquid body therebetween.

6. In the process defined in claim 3, rotating a cylindrical supportingmember continuously while depositing said liquid on said member andcooling the latter to a temperature such that said solidified liquidremains flexible and removing said solidified liquid from said member asa continuous strip.

7. In a process of manufacturing a photographic film unit including alight-sensitive, image-recording medium adapted to be exposed andthereafter processed by a viscous liquid composition supplied in acavity of a container comprising rectangular sections of sheet materialsecured in face relation at the margins of said cavity, and meansproviding a passage for conducting said liquid from said cavity to aliquid receiving space between first and third sheets, one of whichserves as a support for said image-recording medium, said processcomprising coating a first area on one side at one end of a first sheetwith at least a layer of a thermoplastic material, the improvementcomprising:

cooling at predetermined quantity of a viscous aqueous liquidcomposition at least adapted to activate a developing agent for saidimage-recording medium to form a relatively thin, solidified bodysmaller than said first area and having the shape of the containercavity to be formed and filled with said liquid;

12 positioning said solidified body on said layer of thermoplasticmaterial intermediate the edge of said first area;

arranging a second sheet, including a layer of thermoplastic materialand coextensive in size with said first area on said body in coveringrelation thereto with the edges of said first area and said second sheetin substantial alignment;

compressing said second sheet against said body and said first sheet toform said cavity conforming to said body while excluding gas from saidcavity between said sheets;

applying heat and pressure to said sheets at the margins of said cavity;arranging a third sheet in superposition with said one side of a secondarea of said first sheet contiguous to said first area thereof and withan edge of said third sheet contiguous to an edge of said second sheet;

sealing a cover strip to said contiguous edge portions of said secondand third sheets to provide said passage; and

securing said third sheet to said first sheet at the margins of saidthird sheet along the remaining edge portions of said third sheet.

8. The process defined in claim 7 wherein said imagerecording mediumincludes silver halide, said film unit includes a silver halidedeveloping agent and said liquid includes an aqueous, alkaline solutionfor activating said silver halide developing agent.

9. A method as defined in claim 7 wherein said liquid includes anaqueous, alkaline solution for activating a silver halide developingagent.

10. In the process defined in claim 7, embossing said second sheet tothe shape of one side of said cavity prior to arrangement thereof incovering relation to said body.

11. In the process defined in claim 8, beveling the edges of saidsolidified liquid body away from the side of said body in contact withsaid second sheet.

12. In a method of manufacturing a rupturable sealed container having acavity of predetermined shape and volume filled with a viscous, aqueous,photographic, processing liquid adapted to at least activate aphotographic developing agent, said container including a pair ofsections of sheet material bonded together at the margins of said cavityto form a seal completely surrounding said cavity, said sections at oneside of said cavity being bonded to form a seal approximately equal inlength to said cavity and weaker than the remainder of said sealsurrounding said cavity, the improvement comprising:

cooling said liquid to form a relatively thin, solidified body havingthe shape of the container cavity to be formed; introducing said body ofsolidified liquid between said sections;

compressing said sections against opposite sides of said body to form acavity conforming to and containing said body and to exclude gas fromsaid cavity; and

thawing said solidified body to return the latter substantially to itsoriginal liquid state While maintaining the shape of said liquid-filledcavity substantially unchanged.

13. In a method defined in claim 12 wherein said liquid includes a watersoluble, polymeric film-forming agent initially cooling said liquiduntil said solidified liquid forms a flexible body and thereafteraltering the shape of said flexible body to conform to said cavity.

14. In a method of forming and filling a cavity of a rupturablecontainer with an accurately predetermined quantity of a viscous,aqueous, alkaline, photographic, processing liquid containing apolymeric thickening agent, said container including a pair of wallsimpermeable to fiuids and at least one of which is formed of a flexiblesheet material, said method including the steps of sealing said walls toone another at the margins of said cavity, the seal at one side of saidcavity being approximately 13 equal in length to said cavity and weakerthan the remainder of said seal surrounding said cavity, the improvementcomprising:

solidifying said processing liquid by cooling to form a relatively thinbody conforming to said cavity; introducing said body of solidifiedliquid between said container walls;

compressing said walls against each other and said solidified body toconform said one wall to said body and exclude gas from said cavitybetween said walls; and

thawing said body of solidified liquid to return said liquidsubstantially to its original state.

15. In the method defined in claim 14, depositing said liquid on thesurface of a supporting member as a layer of substantially the samethickness as said body, cooling said supporting member to solidify saidliquid, removing the solidified liquid from said surface and cutting itto the size and shape of said cavity.

16. In the method defined in claim 14, rotating a cylindrical supportingmember continuously while depositing said liquid on said member andcooling the latter to solidify said liquid and removing the solidifiedliquid from said member as a continuous strip, said solidified liquidbeing 14 cooled to a temperature such that it is flexible when removedfrom said support member.

17. In the method defined in claim 14, extruding said liquidcontinuously through a die while cooling the liquid to form an elongatedstrip having a cross-sectional configuration corresponding to saidcavity and dividing said elongated strip of solidified liquid intosections, each constituting one of said bodies.

18. In the method defined in claim 14, embossing said sections of saidsheet material substantially to the shape of said cavity prior tointroducing said solidified liquid body between said sections.

References Cited UNITED STATES PATENTS 2,855,302 10/1958 Land 96-763,053,659 9/ 1962 Land 96-75 2,008,271 7/ 1935 Zeigler 5325 FOREIGNPATENTS 345,329 12/1929 England 9l-164 NORMAN G. TORCHJN, PrimaryExaminer J. L. GOODROW, Assistant Examiner

